Low thermal expansion board material

[Jakelian]

Hi,

I am looking for a material in solid sheet (or solid board) form:

- Thickness: Between 1/4 and 1/2 inches,
- Continious working temperature: 180F, no outgassing at this temperature
- Water proof, no or very low absorbance of water,
- Machineable with std tools,
- Accepts/adheres with silicone based adhesives, (after primer application),
- Very low Linear thermal expansion, close to glass, which is around 9 (10-6 m/(m K)
- Thermal insulation is a plus,
- Electrically insulative, and no metals or carbon in material,
- Commercial availability and acceptable cost,

Questions welcomed,
Thanks in advance, I appreciate all thoughts, suggestions and questions,
Jakelian

 

[RPstress]

G-10 glass epoxy is very common and might fit the bill. Available in your thicknesses about 48" square.

This bunch have a lot of similar options:

http://www.par-group.co.uk/high-tem...ass-based-laminates/g10-epoxy-glass-laminate/

and so do Tufnol (they call it 10G)

http://www.tufnol.com/materials-full/glass-fabric-grades/tufnol-grade-10g-40.aspx

The CTE of glass/epoxy is often quite hard to bottom out. I reckon it's between 11 and 16 microstrain/K in-plane (a bunch more out-of-plane, about 40 µε/K). Tufnol seem to claim 12 in-plane.

It should absorb maybe 1% water by weight if exposed hot/wet 'til equilibrium. The above suppliers seem to like to quote mg/unit area and given thickness.

A short glass fiber reinforced plastic might be similar, but I suspect higher CTE. If a thermoplastic is used (not nylon which will guzzle a lot of water) a lower moisture absorption should result.

It should machine ok but will give more wear than you might think.

G-10 is also quite cheap.

 

[Jakelian]

RPStress,

Thank you very much for your attention and effort.

I am reviewing the info you sent me,

Thanks a lot ))

Jakelian